<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <style>
      button {
        width: 100px;
        height: 40px;
        margin: 20px;
        border-radius: 5px;
        border: none;
        background-color: cadetblue;
        color: white;
        background-image: radial-gradient(
          circle at center,
          rgba(255, 255, 255, 0.4),
          transparent 50%
        );
      }
    </style>
    <button>发光按钮</button>
  </body>
</html>
